Total liquids. All I can find is a milk breakdown and we can't so milk.

DS recently started refusing all liquids but his "box" (formula that comes in a juice box). He can only tolerate 2 boxes/day which is 16 oz. He has always refused water so we used to dilute at least 1 box with 60% water, but now he won't even drink it that way. In an effort to get him drinking water we have only been giving a formula box first thing AM and last thing PM....in between water, with yesterday the first day strictly doing this without caving and he only drank 5 oz water, so 21 oz total for the day. I'm not sure if that's enough or how to get him drinking...